My research interest is how chemical elements are synthesized in various astrophysical sites and how these elements are distributed over the Milky Way Galaxy. For these purposes, I’m studying chemical abundances of metal-deficient stars in the Milky Way and its surrounding dwarf satellite galaxies, mainly by stellar spectroscopy. Using observed chemical abundances in combination with theoretical nucleosynthesis calculations in stars and supernovae, I hope to make constraints on how these galaxies are formed and chemically evolved.